National Instruments CAN 372139B-01 - Manual (Page 156)

Chapter 5 Automotive Diagnostic Command Set API for LabVIEW
Automotive Diagnostic Command Set User Manual 5-130 ni.com
For OBD, this field usually does not contain valid information.
Add Data contains optional additional data for this DTC. Usually,
this does not contain valid information (refer to DTC descriptor).
success? indicates successful receipt of a positive response message for
this diagnostic service.
error out describes error conditions. If the error in cluster indicated an
error, the error out cluster contains the same information. Otherwise,
error out describes the error status of this VI.
status is TRUE if an error occurred.
code is the error code number identifying an error. A value of 0
means success. A negative value means error: the VI did not
execute the intended operation. A positive value means warning:
the VI executed intended operation, but an informational warning
is returned. For a description of the code, wire the error cluster to
a LabVIEW error-handling VI, such as the Simple Error
Handler.
source identifies the VI where the error occurred.